Dentifrices and other fluid materials are often packaged in collapsible tubes. These tubes have the advantage of being relatively easy and inexpensive to produce. Consumer acceptance of collapsible tubes has always been somewhat mixed due to the cumbersome nature of the partially used tubes and the difficulty of storage since conventional tubes must lay flat on a horizontal surface. Metal tubes that were first used had the tendency to split or break when too much pressure was applied to the tube while dispensing the contents. With the introduction of plastic laminate tubes, consumer acceptance of tubes was still limited. The plastic laminate tubes have sufficient strength to prevent inadvertent rupture. However, the plastic tubes generally have sufficient memory such that the tubes cannot be rolled up as the product is used, but instead tend to unroll due to the resilient characteristics of the plastics.
As an alternative to tubes, mechanical pumps have been used to dispense fluid materials with some commercial success. These pumps are generally more desirable since they are easier to use and neater to store. The pumps are typically made of a rigid material having a flat bottom to enable the pumps to stand upright and thereby produce a neater appearance during use.
Squeeze bottles have not been particularly successful in dispensing fluid materials such as toothpaste. The highly viscous nature of toothpaste does not easily flow toward the dispensing outlet. The squeeze bottles further draw air into the bottle each time a portion of the contents is dispensed which tends to dry the contents and cause plugging of the dispensing orifice. As more of the contents is dispensed, it becomes progressively more difficult to dispense the contents. In addition, the toothpaste tends to slump to the bottom of the bottle which makes it difficult to dispense the product.
All of the above noted dispensing containers have experienced success in the marketplace. Although the pump-type dispensing containers are easy to use, the expense and difficulty of manufacture has limited the consumer acceptance. In addition, the pump-type devices create large quantities of package waste material when the product has been consumed. Consumer awareness in recent years has shifted to a large extent to consumer goods which have reduced amounts of packaging, thereby reducing the amount of waste at the end of the product's useful life. Attention has also been directed to reusable containers and dispensers which can be refilled, thereby extending the useful life of the container.
Numerous devices have been developed to dispense fluid materials in an easy and convenient manner. One such device is disclosed in U.S. Pat. No. 4,469,250 to Evezich which provides an arrangement using a separate bladder housed within a squeezable outer shell. The shell has a removable cap and nozzle construction. A projection extends inwardly from the base of the nozzle to pierce a foil seal in the bladder to allow dispensing of the contents. Other similar devices for dispensing fluid materials are disclosed in U.S. Pat. No. 4,760,937 and U.S. Pat. No. 4,909,416.
A further example of a pump arrangement for dispensing fluid materials is disclosed in U.S. Pat. No. 4,842,165. This device is a squeeze bottle for dispensing a material without excessive air entrainment between dispensing cycles. The product is suspended in a flexible bag secured at the top end and at its midpoint to the outer container. A suckback valve is located between the dispensing orifice and the flexible bag to prevent air from entering the bag during and between dispensing cycles. An air inlet valve is included in the bottom wall of the container.
The above noted dispensing devices have not been entirely effective in dispensing fluid materials while meeting the consumer needs for cost, ease of use and the environmental concerns for reducing the amount of packaging and disposable containers. There is accordingly a continuing need for squeeze containers for fluid materials. There is further a need for squeeze pump type containers which contain a replaceable inner container to avoid disposing of the entire device.